#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/wait.h>
int main()
{
	pid_t id = fork();
	if(id == 0){
		printf("before: I am a process, pid:%d,ppid:%d\n",getpid(),getppid());
		sleep(5);
		execl("/user/bin/ls","ls","-a","-l",NULL);
		printf("after: I am a process, pid:%d,ppid:%d\n",getpid(),getppid());
		exit(1);
	}
	pid_t ret = waitpid(id,NULL,0);
	if(ret>0)printf("wait success,father pid:%d,ret id:%d\n",getpid(),ret);

	sleep(5);
	return 0;
}
